滑动轴承微动磨损引发不稳定振动研究

Research on Unstable Vibration Induced by Micro Wear of Bearing

从轴承支架微动磨损角度开展某超超临界汽轮机高压转子不稳定振动故障机理研究。基于Archard方程,建立轴承在实际装配和载荷条件下微动磨损分析模型。结果表明:轴承瓦枕与支架之间采用球面配合方式,在该区域内出现局部应力集中。在不平衡力激励下,激振力通过油膜传递到轴瓦。长时间运行后,瓦枕和支架之间出现微动磨损。轴承防跳间隙和插销间隙增大后,轴承失去稳定性,导致带负荷过程中轴颈中心位移较大,振动出现波动。结合某汽轮机上发生的不稳定振动现象进行了分析,根据轴颈中心位置变化特征可评估轴承状态。

A study was conducted on the mechanism of unstable vibration in the high-pressure rotor of a ultra-supercritical turbine from the perspective of micro wear ofbearing bracket.The Archard equation was applied to establish the micro wear model for bearing under actual assembly and load conditions.The bearing pad and bracket are fitted with spherical surfaces.Local stress concentration occurs in this contact area.Under the excitation of unbalance,the dynamic force is transmitted to the bearing pads through the oil film.After prolonged operation,there is microwear between the padand the bracket.The increase in bearing anti jump clearance and insertion clearance results in the loss of stability of the bearing.During the loading process,the journal center displacement is large,leading to vibration fluctuations.An analysis was conducted on the unstable vibration that occurred on the turbine.The bearing status can be evaluated based on changes in the center position of the journal.